Fire extinguisher



May 27, 1930. H. R. MINOR FIRE EXTINGUISHER Filed Sept. 26, 1925 gwvemtoz R 351 i; (lbtowmy z Patented May 27, 1930 v UNITED STATES PATENT OFFICE I HENRY a. man, or ossmma, new Yoax, ASBIGNOB, BY HESNE assremm, r war-ran xrmm a comrm, me, or HEW'YZOBK, n. 1., A conrom'rron or n'nw YORK :Inm nxrmeursm This invention relates to carbon dioxide fire extinguishers, and has for its object the production of a simple and efficient construction whereby liquid carbon dioxide is utilized as the source of carbon dioxide gas and snow for extinguishing fires.

Another object includes the provision of means whereby the entrainment of air is prevented and carbon dioxide is applied directly to the fire with remarkable results and great effectiveness. A further object includes the production of a carbon dioxide fire extinguisher which is light in weightand therefore readily and quickly transported, and whereof the maintenance cost is exceedingly low. I further provide a fire extinguishing medium which is penetrating, non-conducting and of low temperature. My fire extinguishing medium is very valuable for extinguishing fires in unusual or inaccessible places, and being a non-conductor at low tem eratures, it is also valuable and very efficient or quenching electrical fires. It is also valuable and very efiicient for extinguishing solvent fires where such solvent is composed of volatile materials,

such as benzine, gasoline, etc.

I obtain these and otherobjects by the construction illustrated in the accompanying drawing, in which Fig. 1 is a view in elevation and partly in cross section of a construction which embodies the principles of my invention.

Fig. 2 is a view in perspective of a carbon dioxide discharge nozzle, and its gas protecting and gas directing nozzle.

Fig. 3 is a sectional view" of a carbon dioxide discharge nozzle.

Fig. 4 is a sectional view of the valve and Fig. 5 is a sectional view of the end of ,the siphon tube in the cylinder.

Like numerals refer to similar parts throughout the several views.

The value of carbon dioxide gas and snow as a fire extinguishing medium has been known for a long time, and many attempts have been made to apply the gas in the most eflicient manner. In thisconnection, particular eifort has been directed towards the quenching of fires with carbon dioxide where .50, special hazards exist, as in dry cleaning establishments, in chemical laboratories, in the oil or rubber industries, and other similar highly inflammable industries or storage places.

I have discovered that if the entrainment ofair therewith can be 'revented, carbon dioxlde gas becomes one o the most eflicient fire extinguishing mediums known, and the idea V as conceived by me, and embodied in a ractical application includesmeans where y the gas is dlscharged within a protecting, shield or device which surrounds the gas which is to be applied to the fire. Such a protecting shield or ev1ce not only prevents the entrainment of air along with the quenchin gas, but has, in addition, also a secondary e ect of great importance on the gas discharge as will be hereinafter explained. Practical tests carried outby-me with airrestricting means for preventing the entrainment of air, proved the efliciency of carbon dioxide as a fire extinguishing medium. In this instance, the medium was applied directly to encase or blanketthe'combustible material to thus completely prevent combustion in, a most surprising manner. Any suitable means for preventing the-inrushing of the .surrounding air will answer the purpose. One difiiculty encountered in .carryin out my practical tests where a nozzle in ad 'tion to the cone was employed has been that where liquid carbon dioxid is employed as a fire extinguishing medium there is a tendency of the great degree of cold caused by the release of the liquid and the resultant expansion of the same at the instant of release into gaseous form, toicause the chilling to a very low temperature of the nozzle or other means employed for delivery of the liquid to thepoint where it is released. This tendency is created when the expanding medium at or after the instant oflrelease is permitted to'come in close contact with the exterior surface of the nozzle orof the device employed, with the result that the column of liquid in the nozzle is extracted of its heat causing such column to freeze'up within the nozzle and choke the bore thereof. The best results as a fire quenching medium, as I have found, are obtained when the liquid carbon dioxid is released and permitted to expand into gaseous form which i produtes snow, so that the gas is applied to the fire mainly in the form of a finely divided CO snow at a temperature of approxlmately 110 below zero so that certain advanta es which are obtained consist in a higher specific gravity from the use of CO snow rather than 00 gas, also the cooling effect available 1s of material help. I find an open ended vessel or hood having walls of preferably non-combust-ible material most satisfactory. As a practical embodiment of my invention for applying carbon dioxlde, I have shown a cone-shaped vessel 10, or an equ valent rectangular vessel 11. The cone-shaped vessel or shield is of substantial length, that 1s, of such length that fluids leaving its flared end are, due to gradually increasing diameter of the shield, reduced in their velocity so that they entrain substantially no air. The ves sels are provided with an open mouth 12 and have one or more carbon dioxide supplying nozzles 13 (or 13) enclosed therein. These nozzles are connected by a flexible metal hose 14 to a quick release valve 15 on a cylinder 16 of desired dimensions. This cylinder is designed for holding the liquefied carbon dioxide as the source for the gas and it is normally about two-thirds full of liquid. A siphon tube 17 extends from the valve into the gas to near the bottom of the cylinder. At the lower end of this tube a recess 18 is provided to equalize the feed.

The cone or nozzle is shown, in this instance. as being exteriorly tapered toward'its base and away from the line of discharge of the gas through the bore thereof, and is provided with a threaded nipple 20 for attachment to a connection tube 21. The cone or nozzle is also provided with a convenient nut 22, and a longitudinal bore having a sharp aperture 23 of restricted area. for the discharge of the gas. If desired, the bore of the cone or nozzle may be of gradually constricting area towards the discharge aperture 23. In the operation of the device the gas, when released from its pressure by its discharge from the orifice 23, rapidly expands, and in its expansion absorbs heat from its surroundings. Since, however, the expanding gas, by a structure and arrangement of cone or nozzle, of the character described. discharges with the least possible contact with the exterior surface of the nozzle or cone. it does not extract or absorb heat from the body of the nozzle or cone and, hence, from the column of the liquid or other form of the gas contained in the bore of-the cone, which, otherwise, might cause such column of liquid or gas to freeze up within the cone or nozzle bore. It is the feature of reducing actual contact of the expanding gas with the exterior surface of the cone or nozzle to the least possible point, that contributes to this important feature and characteristic of my invention, in whatever physical way this reduction of contact may be secured.-

The cylinder is provided with a handle 25,

and is adapted for easy transportation. The

apparatus is light in weight in comparison with the amount of gas used, as one volume of gas compressed in a cylinder is equal to about 450 volumes at atmospheric ressure.

The use of the siphon tube has the a vantage of delivering the gas at a uniform pressure without undue ebullition, and there is no great tendency to freeze, .due to the absorption of heat. The purpose of the syphon tube is to remove the liquid portion of the gas first as CO snow is made only from the liquid portion and it is obvious that if there was no siphon tube only gas would be drawn off as the liquid would boil as the reduction in the pressure was accomplished. The apparatus is always ready for quick service and when needed, the quick relief valve 15 is opened and the gas is directed by the hood towards the flame which is choked thereby. The heavier than air carbon dioxide gas and snow afi'ords a very effective means of extinguishing concealed flames or embers in inaccessible places.

While I have disclosed a specific embodiment I do not desire to be understood thereby as having limited myself unduly, as various forms falling wholly within the spirit and scope of my invention will present themselves to those versed in the art.

What I claim therefore, as new and useful, of my own invention and desire to secure by Letters Patent, is: I

1. The method of extinguishing fire which comprises projecting a jet of fire extinguishtainer of the liquid, a nozzle having-a re-' stricted discharge orifice and in free communication with the container for discharging the liquid and an outwardly flaring shield completely enclosing at its smaller end said nozzle into which the nozzle discharges, said shield being of such length that the discharge when issuing from the shield no longer has suflicient velocity to entrain substantially any air.

3. In a fire extinguishing apparatus employing liquid carbon dioxide discharged without entrainment of air, the combination comprising a container of liquid carbon dioxide, a nozzle having a restricted discharge orifice and in free communication with said container so that liquid carbon HENRY R. MINOR. 

